This section provides background information to facilitate a better understanding of the various aspects of the disclosure. It should be understood that the statements in this section of this document are to be read in this light, and not as admissions of prior art.
Generally a ring gear is a ring-shaped cylindrical disk with teeth cut into the periphery or interior face of the rim. Typically a ring gear is manufactured of steel or a steel alloy for the strength properties and mostly used in transmissions for automotive or aircraft applications. The teeth of the ring gear are driven by a smaller pinion gear or planetary gear. A common function of the ring gear is to transfer torque from the pinion to a flywheel of an internal combustion engine.
In use, ring gears are often low rotation or even stationary. In high rotation applications, e.g. 5,000 to 10,000 revolutions per minute (RPM), centrifugal force is significant and causes high stress on the teeth which can result in deformation and/or breakage of the teeth. In order to combat the high stress levels created by centrifugal forces, additional stiffness is required. Increasing the amount of steel material is a way to increase the stiffness of steel. Increasing the steel content adds mass which, in turn, increases the centrifugal forces created by the spinning ring gear and counteracts the additional stiffness gained. Additional mass is especially undesirable in aircraft applications where weight negatively affects aircraft performance.